Tempering/Quench lines

[ausjulius]

Originally Posted by archer

A while back Alex mentioned a blanched area on a blade caused by quenching. What causes black or darkened quench lines? While we're at it note that the third blade shows a V chevron pointing towards the blade tip. The two upper blades show the first quench line dark and pointing toward the hilts then each show two more quenches with the V changing directions. What is that all about besides I have to much time on my hands. lighting was bad but i think you'll see what I mean.

Thanks, Steve

it is differential hardening,
the tips on the first two are both harder than the blade area and then again softer at the hilt.

the last knife seems to be only harder in the main part of the blade than the hilt.

it is interesting to see this obveously the arab who made them intended them to be used, id say most later ones would be all like the lower 3rd knife..
no doubt the top 2 were made at a time when these were used frequently as weapons..